Heavy Duty Braking Transistor Modules. Overvoltage Solutions for AC Drives. Braking Transistor and Braking Resistor modules are used with AC drives to eliminate overvoltage faults. The use of these modules permits controlled braking of the AC drive and dramatically shortens the time required for motor stopping as opposed to coasting. Bonitron M3452 Heavy Duty Braking transistors are used in applications that have continuous or high duty cycle requirements. The modules are used with drives that have inadequate or no internal braking transistor. They work with any AC drive system with DC bus field terminals. The Bonitron M3452 Braking Transistor modules monitor the drive DC bus levels and control an IGBT power switch which is connected to a resistive load for dissipating the regenerated energy. Standard modules are available rated up to 1200 Amps DC and Braking Duty Cycles up to 100%.